One of the things that could be done to curb groups from monopolizing NM's is to set up a system similar to FFXI's ENM system. This entailed NM's that were spawned, but for 14 the developers could extend it to all NM. The particulars of this system were that anyone who fought the NM would not be able to see it the next time it was spawned for a fixed amount of time. This would allow groups to rotate claims on the higher tier NM's that require groups to bring them down.

Alternatively for smaller NM's that can be easily soloed by higher rank characters, simply make the NM unable to drop the special item if the person is not within level range (10 ranks within the NM) so that people still have to group up in order to kill it and get the drop without worry of high rank solo individuals rotating to get claim and bring the NM down trying to get the drop. For this to be more beneficial, developers could alter the drop rate (3~8% adjustment depending on difficulty) so that groups would not have to constantly fight the NM for the drop or worry they might get beyond the rank limit before getting the specific drop they are camping the NM for.

To me, these would be far better ideas for curbing RMT or like minded individuals rather than tossing the claim system to the wind. Additionally, the wording of how the other system (no-claim system) works left me under the impression that the drop could still shift to who ever generated more enmity on the NM through the duration of the fight. This would only serve to cater RMT or like minded individuals not curb it.